Air track



Jap. 22,1963 I* l w.R.-BER-TEL`SEN 3,074,764 AIR TRACK s sheets-sheet'z VFiled Dec.` 3, '1959 INVENTOR; -V will am f2 Ee'cle/a Jan, 22,` RQ BIER-TELSEN AIR TRACK Fil-ed ngc,- 5, 419594 INV ENTOR.'

winiam R. Beringen,

- liarn E. Martin, Kcwanee,

i air track comprising .a low friction adequate control and'traction'undcr. all conditions' of use' regardless of the physical4 condition of the surface being ricks, power shovels, drags,

'driving parts by the` thereby.

sired traction AIR TRACK,v

Ncponset, Ill., assignor, by vdirect and' mes'ne assignments,

to Martin Engineering Company,

poration of Illinois Filed Dec. 3, 1959, Ser. No. $57,213;4

17 Claims. CI. 30S-11) j Neponset, Ill., a cor- In general, this invention relates to a track type tractor or other vehicle incorporating new high speed and light -weight driving means er function to propel such tractor or vehicleV across various 'kinds of terrainor across wet or-swampy regions, and f over water with equal facility.

More specilically, the present invention is directed to an air Vtrack assembly adapted for 'driving or manipulating a 'vehicle or other mobile unit on land or water, with the mechanism supplying traversed. To further elaborate'on the nature and embodiment of the air track assembly of the present invention,

oftwenty-iiv'ev percent to Wil' Ill., and twenty-live percent' this 'I United States Parent Ov motivating mechanisms that tion to 'illustrate-'one adaptation companying drawings forming apart of this specitication.

In the drawings: l

FIG. 1 is a side elevational view partly in section of a.

diagrammatic arrangement thatdepicts the general prin-lj ciple-underlying the air vtrackmechanism herein devised and disclosed;

FIG. 2 is a top plan sectionalview ofthe demonstrating unit shown in FIG. l as such means appear when viewed substantially along the plane of the line 2 2 in FIG; 1;

FIG. 3 is another of the pressurized air' lubrication principle use'd in the design of the air track of the present invention; 'a FIG. v4 is a side elevational view of a representative vehicle incorporating the air track of the present inventhereof which is obviously applicable to any type `of a -vehicle or piece of equipment that requires positive-traction and stable sup- I port;

mechanism may be employed as the driving means for farm tractors and farm vehicles; for military vehicles such as tanks, carriers, personnel cars and transports; for utility-cars such as used in industry, or byranchers and explorers; for snowmobiles; for use in connection with agricultural equipment and implements-that are adapted for the care and cultivation ofthe rice and sugar cane areas; and for the 'support or locomotion of large derearth 4movers land other analogous equipment.

One of the objects of this` invention is to'provide a.'

power mechanism to bodily actuate a mobile unit, wherein the mechanism emsupport and/ or vehicle or other bodies a-controlled supply of air under pressure to part' or separate the coacting movable and stationary assemblies o f the traction power mechanism to establish an air cushion lubrication and air uphel'd support for the mobile unit per se upon the driving track mechanism. Another object is to provide an air track vehicle motivating assembly that is light in weight, simple in designl and low -in rst cost, and one thathas low cost'maintenance as `well as low operating cost.

Since the air track is such as to provide a simple light y weight-assembly, extremely high speeds maybe attained,

to which may be added the facility of providing a completely. assembled vehicle andtrack' contributing vtothe attainment o f'a low silhouette for stream line purposes and for low clearances, etc., not to overlook the obvious benefits of a low height vehicle for military uses and operations..

Another object is to provide a light weight, air lubricated power track that will operate etliciently under adverse conditionsin mud,'snow, on ice, in clay or sand; 'and which will counteract fouling of the essential coacting road bed lsupport for the air track andthe vehicle carried Still 'further objects and advantages reside in the use fof a light weight high speed air track that is capable of traveling over the ground with very low soil compactness resulting from'the track tread members; the exibility and-feasibility residing in a selectivity of providing, long air track u'nits or very wide shorter units designed to carry any given load and to produce any amount of dcfor a particular load; the self-cleaning ability o f the. track; and the optimum minimum frictional operationof this air track to simultaneously sustain heavy loads substances or materials forming the' .FIGs 5 is a side elevational view of one of the air I track assemblies shown inv section 'along a vertical plane taken generallylongitudinally of thetra'ck unit; FIG.' 6 is across sectional view of the air'track taken liorizmtally thereof and substantially as the unit appears when viewed along the plane of the line 6-6 in FIG. 5;.

FIG. 7 is a 'general schematic view of the air track `driving and'operationalmechanisms, the left hand track being shown in section as it would bel seen when viewed alongthe plane of the 1ine.7'.7 in FIG'. 6;

FIG. S-'is a side elevational view of a modified air A track structure, partially broken away and in section, this arrangement introducing a greater, ground contact liexi` bility to reduce the rigidity of the track;

-FIG. 9 is a side elevational view ofanother modified construction-of air track depicting a still further way in which to overcome ground contact rigidity of an air track of the present-invention;

FIG. l0 is a vertical cross sectionalview ofthe. modi' ed tracklin FIG. 9 as the same appears when viewed substantially along the plane ofthe vline 10-10 in'FlG. 9; FIG. l1 is a fragmentary vertical'cross sectional view vof another part of the airv track shown inFIG. 9 and as taken substantially along the plane of the-line 11'-11 in FIG. 9;

FIG. l2is a general power drive means adapted for Arnovingthe track to propel a supported and attached vehicle;

FIG. '13 is a vertical cross sectional view taken along "f the propulsion end of the power air' track shown in FIG. 1'2 onvthe plane-ofthe line'13-13 in that view;

FIG. 14 is an other vertical cross sectional view of the modified air track of FIG. 12 taken along a plane of the line 145-14 in FIG. l2 remote from the driving means 4 location 'of this track;

FIG. 15 portrays a side elevational viewin section` taken 'in a vertical plane longitudinally of a modified structure representing a conveying apparatus embodying the same principles of operation as the air tracks illustrated in the above noted views, theapparatus in FIG. l5 demonstrating the adaptability of the air track means to the transport or carriage of articles such as cargo,

merchandise, wares of all sorts, etc.;

FIG. 16 illustrates a vertical cross vsectional view of the" conveying apparatus as it appears-when viewed substana tially'along-the plane of the line 16-16 in FIG. 15;

FIG. 17 illustrates a side elevationalview of an air diagrammatic view in side elevation, partially in section, to demonstrate a further adaptation side elevational view of a'modiied air track structure incorporating a Apositive interlocking track construction employing a plurality of articulated air shoes all working in cooperation with a iiexible track, the air shoes including spring means to introduce a combination of air lubrication and resiliency of the track to pass over irregularities and ground obstructionswhich are accommodated under automatic track deformations;

.FIG.418 illustrates another view of a diagrammatic naturewith parts shown in section and as some of the articulate air shoes will react to a ground obstruction, continuing to furnish support for an attached vehicle while permittingtrack deformation, but maintaining the same eic'ient a'ir glide or cushion reaction upon the track moving relatively' to the shoes under the -forward progress of the track assembly; and

FIG. 19 is a vertical cross sectional view of one track shoe unit, taken travcrsely to the views shown in FIGS.

17 and l8, to illustrate further details of construction relating to the articulate independent resilient suspension of each shoe and to the guiding structure that holds the y shoes in their operative relation to the track to maintain a given line of travel for the track.

Primarily the principle herein evolved as it is applied to the advantages and, beneiits derived from the simple, light weight air track of the present invention may be best understood with reference to FIGS. 1 and 2 of the drawings. i The apparatus there shown is supplemented with legends to aid in interpreting the essential assembled elements used to show how two coacting parts .may be relatively moved or actuated under extremely low friction conditions while supporting a load or any object on one member to .be carried by an air' cushion established between thecoacting parts that makethis arrangement feasible.

In FIGS. l and 2, the apparatus comprises a movable support 1, a fixed support 2, and an operative system 3 to supply air under pressure into the space between the supports 1 and 2 to establish a pressurized air cushion at 4. Movable support 1 is made as a solid disc 5 having a hub 6 to carry a shaft 7 supporting the weight ofa supported instrumentality which shaft is guided for rotation in appropriate means such as the fixed bearing 8, etc. Any suitable driving mechanism may be used to move the support 1, which in this case is employed as a rotatable xture for purposes of explanation. The stationary or lixed support reactionary bed 9 providing an air box or plenum 10 that receives the discharge duct 11 of an air supply blower' or pump 12 that is controlled and driven by a suitably connected'motor 13 as the power means to operate the blower. d

The bed 9 is mounted upon a rigid frame 1 4 and the bed provides an annular rim 1S to establish an air exhaust path 16 in conjunction with the disc 5 and at right angles to the disposition of the air cushion 4.,- Bed 9 is further provided with openings or orifices 17 to' permit air under pressure to ow into the space of the area between-disc and bed 9 as the air'is delivered from within the air pressure source such as the blower 12. p

With the apparatus shown in FIG. 1, it is possible to establish an air cushion at 4 that is buoyant enough to support the disc 5 in spaced relation above the reactionary bed 9, with the motor-blower means of the operative system 3 maintaining a given pressure value of air between the supports 1v and 2te cause the disc to move or rotate on said air cushion spaced above the adjacent surface of the reactionary bed 9. Air spills out of the annular exhaust path 16, but this lost air is continually replenished by the blower 12.

Conceivably, the exhaust path 16 can be made extremely small under reduced clearance tolerances, or suitable air retention glands and the like can be incorporated between the relatively movable supports 1 and 2. However, for simplicity of design and for complete freedom of operationfitis desirable to merely establish a simple convenient coacting clearance relationship between sup- 2 comprises a hollowv l ports 1 and 2, together with a selected pressurized air cushion that will hold' disc 5' ina given controlled suspension for frictionless operation in its movement relatively to the bed therebeneath.

It should be observed and kept yin mind that the air pressures need not be excessive and thatfor manyA .ordinary purposes the pressure can bein the very low ranges. Obviously', theload provides the basis for establishing the pressures required in relation to the coacting e'iective areas of the two supports. As-an example, a '12 inch diameter disc such as 9 can support a load of approximately 2260 lbs. on a sustained airv pressure cushionof 20 lbs. per sq. in. Raising the air pressure value to 40 lbs. per sq. in. immediately establishes a friction free load carriage or support of about 4520 lbs. or 2% tons, all lbeing' upheld-or sustained by a one foot diameter disc.

The' feasibility and efficiency of providing a friction free suspended load should be apparent from the description and explanation above given with reference to the diagrammatic apparatus disclosed in FIGS. 1 and 2. FIG. 3 dcmonstates another apparatus adapted to the application of a friction-free load carrying arrangement as utilized to provide an air uid cushion or physical separation between two relatively movable members or supports of a coacting instrumentality of the kind herein disclosed.

FIG. 3 shows a fixed support 18, a movablesupport 19, a shaft 20 secured to hub 21 above the support 19 with the shaft depending througha bearing 22 'in the hub 22a on the fixed support 18 to4 sustain or suspend a load by means of the shaft 20. The'lixed support 18 comprises an air box or plenum 23 which is supplied with air under pressure through a suitable duct 24 having communication with an air pressure supply source, and openings or vents 25 bleed pressurized air through the bed 26 of the tixed support. The fixed support 18 is constructed with a peripheral-rim 27 carrying an inwardly directed overhanging radial flange 2S. Bed 26, rim 27 and ange 28 lconfine the movable support disc 29 within the air supply area and over the cushion zone above the lixed support 18l with the ilange28 forming a maximum upward separation stop for the discv 29 in relation to the adjacent reactionary surface 30 of the fixed support 18.

In operation, the FIG. 3 device performs the same friction free task as does the apparatus ot FIG. l, with FIG. 3 introducing a stop means to limit separation, Aif desirable, between the fixed and movable supports 18 and 19. In both the devices of FIG. 1 and FIG. 3, itshould be noted that the exhausting air functions as anti-fouling means keeping the air cushion areas free from dirt, moisture", vand-foreign matter to insure.friction free operation. The exhaust air in the-FIG.A 1 construction for'n'is acylindrical upwardly directed curtain of air about the structure above the disc A5. In .the FIG. -3 unit, the air fans out radiallyinwardly across the face 'of disc 29 to be generally upwardly diverted by hub .21. to aid in maintaining the top of the assembly free from dirt, moisture and foreign matter..

The above described attributes and benets are all embodied 'into the air track structure of the present invention t'o provide amechanism having unlimited uses and applications in connection with mobile vehicles, implements and other kinds of machinery.

' FIG. 4 shows a vehicle 31 suitably supported upon and propelled by air track assemblies 32 and 33 of 'substantially identical construction. In general, an engine 34 on vehicle 31 is arranged to drive through a speed changing' transmission 35 that includes suitable independent drive shafts 36 and 37 connected with the driving wheels 38 and 39 of the air tracks 32 and 33. The air track assemblies 32 and 33 will be described by use of the same reference characters which willdenote similar parts and members. FIG. 7 shows both tracks 32 and 33.

'comprises a continuous flexible wheel 38.

or tread 40.

The belt or traction tread 40 is made with exterior cleats 43 to engage and grip By introducing air under pressure is'created in the air confining and to cause the tread to pass v.vehicle body 31a.

.further be employed to suspend or carry-the vehicle body 31a from the air treads.

With reference to' FIGS. 5, 6 and 7, the air track 32 tread 40 entrained over a load carrier in the form of an ai'r box or plenum 41 f to conform with the exterior shape or contour of the box'7 the tread leaving the carrier box at the power end of the track to encircle a 180 degree portion of the drive wheel 38 of the air track 32.

-Box 41, acting as a load canrier, is made to fill in all of'the space within the tread loop and also encircles certain tangential portions of the driving wardly at 42 to dispose the tread 40 in an upwardly inclined relation to the front of the vehicle to pass or climb o'ver obstructions encountered-in the line of travel of the vehicle.,

Whee1'38 is actually in the form-of a smooth exterior pulley to function as a means to drive the belt or tread 40'and to 4convey the tread about the air box-41 to keep .the belt or-tread in motion to roll the vtread along or upon the ground thus forwardly advancing the air box carrier -within the interior loop of the run o f the belt ground, while the interior. surface part of the belt or tread is flanked with laterally outwardly positioned rims or guide flanges 44 and 45 that are Supplied to straddle both'the'wheel 38 and the air box 41. 4This arrangement provides a combination air adjacently situated and aligned drive wheel 38 that are both covered by the moving belt or tread '41 which -is guided along 'or .over the two' described instrumentalities by means of the retaining flanges 44'and 45. i

The air box or plenum 41 has air dispersion openings or orifices 46 formed through its' lower wall 47 for comthe tread and box. into the air .box 41 to leak -or vent out of the openings 46, an aitr cushion space 48 existing between 41 and the upper surface munication with the space between the lower portion of the box of the ground engaging will provide an air lift or support upon tread 40 whereon to float the box 41 out of physical contact therewith freely under the air box in friction free relation as previously expressed under the principle of pressurized air lubrication as explained broadlywith reference to'FIGS. 1 and 3. Some very small air bleed vents 49 may be provided'in the top 50 of the box'to float the top run of the belt or tread 4 0 over the top'of the box-41. Very little air-pressure is requiredv over the top of the box to carry the top trun of the tread 40 since only theweight of the tread per se need be overcome. But the lower coacting and relatively movable supports involve upholding or carrying the weight of the entire vehicle secured to thezbox, with the "the forward end of box41 is angled up-v belt or tread 40. This action' wall into the hollow drive axles or shafts 36 and 37. Suitable air collecting ring units 56 and 57 permit inletair comis employed for driving the pump 'munication from within axles or shafts 36 and 37 through i' boxesor plenum means 41 to create ,the air cushion separation between the boxes and their Iadjacent track treads by holding the boxes upwardly and free of the belts or treads 40.

-Pump 63 may be driven from the engine 34 under,

selective control means to initially establish an air pressure condition, but in FIG.v 7 a yseparate electric motor 66 or blower 63 to provide an independent air source that is not connected with-'the-main prime mover of the vehicle.

trol valves'71 and 72 with the air inlet lines 59-and 60. the supporting surface or` tubes '67 and wet or watery conditions are encountered b y the vehicle. One of the advantages of providing wheels- 38 and 39 box or plenum 41 and an with air'inlet openings is to thereby introduce a means,

' the treads 40 over the drive wheels 38 vand 39. Air entry out of belt contact.

.73 adjacent the arched lwall FIG. 7 further shows supplemental air intake means `which are depicted by snorkel tubes 67 and 68 that have air entry fixtures 69 and 70 disposed at an elevated location on the vehicle and which tubes connect through conr[his arrangerrient permits selective air intake either through the wheels or independently of the wheels through 68 which choice vwould berequired when by limitedsuction, to .cause better tractive .belt grip of would still be well insured by air intake' through the openpositions in the b elt free 'portions ofthe wheels which are the box also carries the arcuate side anges 7'5 and 76 that are seen in FIG. 6 and which ank the belt free half of the wheel 38.

Theco'nstruction of the air track 32 just described in# volves the use of a fairly rigid track except for the external driving belt or tread 4t) which is made of a tough but resilient material such as reinforced rubber, synthetic box operating within the tread both for bodily support and for vactuation over the ground or road in caterpillar treadaction'and manipulation- FIG. 6 illustrates generally how the vehiclebody 31a may be carried or supported from the pairof air tracks,

' only one track 32 being there shown. Suitable bracket -and structural beam members ST1-may be secured to the air box portions of the treads to support the body 31a. Also, the axles or hollow shafts 36 and 37 that are attached with the-wheels 38 and 39 are journalled in the Other braces or frame members may is diagrammatically shown at and 39 that are provided with inlet openings or vents'55 located about their p eripheriesto permit air intake or passage rubber or the like, No boggies or other wheelmeans are used and only one drive wheel is employed in conjunction with a light weight hollow air box or plenum chamber. This simple structure is-made possible by reason of the vair lubricated tract that provides a supporting air cushion offering substantially no friction depending upon the coritours'- of the adjacent surfaces of the tread and box or wheel means. Conceivably a drive wheel or other power means could be ter'nalperipheral point or area and to use an a-ir boxto completely till the .tread loop. While 'this is also feasible, such an arrangement does sacrifice the compactness possible with the--sing'le wheel drive within the tread loop as shown inFlG'S. 4 and 5.

Referring now to FIG. 8, this air track 77 embodies.

the use of two smaller driving wheels such as 78 and 79,

one of which may be an idler if desired, and the tread V i 80 follows thewheel peripheries and encircles a -coruposite -air upsloping ends 82. and 83. The air box or plenum 81 comprises a dual chamber unit having a hollow dummy metal chamber 84 and a chamber 85 constructed from tough but resilient flexible material that is connected with and underlying the metal chamber 84,

` Air under pressure is supplied' through 'a suitable air duct 86 into rthe resiliently walled chamber 85 to keep the physical portions thereof well ina-ted and to bleed air out of openings S7 to establish an air cushion guideway'between the bottom wall 88 of chamber-'85 and the adjacentfacc 89 of the running tread 80.

The track 77 -is constructed to provide a resilient Frein pump 63 air under pressure l lines 64 and 65 to deliver this air, supply under pressure into the ducts 52 and 53 of the air lThese openingsappear at the zone 7 4 of box 41 which part of t employed to engage the tread at an exbox or composite plenum 81 providing double I be varied in depth to accommodate certain conditions of operations. This track, therefore, introduces a flexing -ground contact' face having obvious operational advantagesl and benefits. l

FIGS. 9 to Il portray another construction having surface dellccting or flexing ability. The air track 91 involves the use of a drive wheel 91u, an air box or plenum 92, and an air supply duct 93, with air exit vent openings 94 opposing a tread or belt 95. The tread 95 is hollow and inflated .like a vtire and comprises-belt tube having earth engaging cleats 97 on one face and longitudinal tapered track ridges 98 on its other face for drivingcontact with corresponding grooves 99 in wheel 91a while the ridges are also adapted for guidance along grooves 100 that surround the o utcr contour of the box or plenum The track 91 thus has the facility of giving and ilex- 4ing over obstructions such as member 101 in FIG. 9.

While the flexing takeup in track 77 in FIG. 8 is absorbed absorbs lthe shock of ground obstructions in the tread or belt 96 per se. feature to introduce a frictionless operation between the relatively moving elements comprising the tread and air box'structure.

FIGS. 12, '13 and 14 show the air track principle incorporatcd into a unit using an air box or plenum to till Athe ent-ire tread loop and providing a toothed drive wheel to mesh with tread imbedded teeth as a positive tread drive mechanism. The air track 102 comprises an lair box 103'having a forked or divided plenum end forming spaced terminal sections 104 and 105. A tread or belt 106 encircles the' air box unit and incorporatesan imbedded flexible metallic belt 107 carrying teeth 108 that ride in the peripheral box groove 109 and in the space between the plenum end sections 104 and 105. A toothed drive wheel 111) is driven by shaft 111 that enters the split plenum space 112 vthrough an opening in section 105- that accommodates a suitable shaft bearing 113. Openings 114 are provided in the plenum for the air cushion support of the plenum or box upon the tread 106. Small bleed vents 115 may be used to aid tread travel across the 4top of the air reservoir means comprising the air box or plenum 103.

FIGS. l andjl6 have been added to illustrate another application ot' the air track principle in the form of a conveyor 116 providing an air cushion belt run to support and convey articles. The unit primarily comprises a beltv'117 that is carried by pulleys 11S and 119, one or both of which may be driven, and the belt 117 passes over or across the top wall 120 of an air box or plenum 121. A blower 127 is suitably driven by a motor 123 to supply air under pressure through duct 124 into the interior of the plenum chamber 121 for pressurized dispersion of air through the apertures 125 in wall 120 of the air box or plenum. The air box or plenum 121 has upright side guide flanges 126 and 127 to form guide means for the articles 128 and for the belt 117. Under operation the belt 117 rides over a pressurized cushion oE air that is maintained under the belt 117 and above wall 120 of the air box or plenum 121 to establish a frictionless lubricated relationship between the belt and plenum while conveying the articles Such as 128 along the conveyor.

It shouldbenoted that the construction just described and shown in FIGS'. 15 and.16 may be further applied and adapted to provide moving sidewalks and moving escalators embodying the same conveying principles and air lubrication mechanisms. .Many of the principles depicted may be reversed without changing the inventive concept. moves relatively to the air cushion mechanisms. In the tractor illustrations a forward motion is developed to Both tracks utilize the vair cushion 8 i bodily move a vehicle or the track assembly in a give direction. In the conveyor illustration, the entire as-A Sembly remains in one location, b ut thcbclt encircles the cooperating airunts.

FIGS. 17, 18 and 19 show another form-of the invcntion which provides a power track assemblyv thatmay be used to move a vehicle. be used as a conveyor to move the b elt or track about .the air cushion instrumentalities all without change in the fundamental features here developed. While vthe track assembly is shown as ground supported and passing the-reover, the same may be used to convey heavy articles having somewhat irregular contours accommodated by the automatic actionof the articulate air shoes.

l The track assembly 130 in FIGS. 17 to 19, comprises a central track boxor plenum section 131 forming an uir chamber-and providing suitable structural elements such a's 132 and 13S-.to connect with-a vehicle or other by the air box orplenum 85, the track 91 in FIG. 9

unitlto be vrendered mobile, element 132 serving as ahollow duct to constantly supply air under pressure into'the box 131 to serve the articulate shoe means comprising air conduit means between the box and. track.

A plurality of shoes 134, 135, 136, 137, 133, 139 and 140 surround the box 131 and-these shoes have sliding contact with the interior peripheral surface area of a continuous flexible track 141. The shoes are all similarly supported from the box 131 and guided for predetermined operation by duplicate mechanisms. The same reference numerals will be used in each shoe assembly Shown.

In all modications shown the track or belt Each shoe has side links 142 and 143 `pivotally connected upon shoe pins 144 and 145. Both pins 144 and 145 as Well'as the shoe ends of thelinks 142 and 143 lie in'recesses 146 and 147 formed centrally in opposite shoe faces. This produces a flush sided shoe link arrangement to guide along the flexible belt or track 141-in the trough thereof defined by the radially inwardly directed belt flanges 148 and 149.

Each link 142 and 143 is slotted at 150 and 151 for guidance relatively to pins 152 and 153 secured to the box 131 to permit' both translatory. and pivotal movement of the shoe links. Box 131 and each shoe have aligned sockets or recesses 154 and 155 to receive opposite ends of an expansion spring 156 therein. Spring 156 functions to hold the shoes extended as limited-by their respective links 142 and 143, with the shoes slidably in contact with the flexible track 141.

The shoes 134 to 140 are all hollow as shown in PIG. 18. Individual air lines such as 157 in FIG. 17,- conneet the box 131 with the shoes to supply pressurized air to the shoe interiors. As best -seen in FIGS. 18 and 19, air is bled or expelled through the bottom shoe walls 158 out of apertures 159 into the trough area of the track 141 to establish air cushions between the shoes and track for minimum frictional Contact between the described members.

A drivewheel or pulley 160 is drivenby a suitable power means from an attached vehicle or power unit connected with shaft 161, the wheel having driving con` 'tact with the'trough portion of the track 141 to advance lthe track assembly over a supportingA surface.

When traveling over generally flat terrain, the track assembly will function with the various mechanisms occupying the position shown in FIG. 1. Upon contact with a road irregularity, the shoes and track will assume positions of conformity with respect to the'road rise or depression of the latter may be encountered. FIG. 18 shows one such occurrence.

Attention is directed to the compound action obtainable with the multiple shoe arrangement. Each shoe has two pivotal centers, the aligned pins 144 and 145, and the aligned box pins 152 and 153. The shoes may bodily swing about the box pins or individually swing on the links by means of the shoe pins 144 and 145. The shoes may also move bodily upwardly as guided by the link slots of the links as the slots coact with the box pins 152 The same arrangement can with said carrier into said chamber for dispersion out of and 153. Obviously, many compound motions are possible with the shoe suspension mechanism`einployed. Shoe swing or rotation is limited by the recess walls 162 and 163 shown in FIG. 17, which indicated walls'are made to contact the'adjacent edges ofthe shoe links confined within the shoe recesses'146 and 147.

IThe top shoe assemblies may be lighter in construction since they only need to carry the upper run of the track 141. Preferably, the upper -shoes 139 and 140 are only provided with a few smaller .airbleed openings 164 as seen in FIG. 18 toair cushion the track overpass along theV track assembly.

. The above description has been directed to a number ofselected adaptations of the air cushion principles to caterpillar tracks and to analogous arrangements all serving to provide efcient apparatus to perform the functions depicted. While certain changes and modifications in the exact designs of the various elements or combinations thereof are contempla-ted 'without departure from the fundamental inventive concept, the extent of such variations shall, however, be governed by the breadth and scope of the language appearing in the hereinafter claimed subject matter directed to the air track means of the present invention.

What l claim is:

1.'An air track assembly comprising a carrier, a drive vwheeldisposed beyondone end of'the carrier, anda liexible track eritrained over both said carrier and drive wheel, said carrier and drive wheeltogether providing complementary housing means that fill the'interior of said ilcxible track, said carrierr having a'hollow chamber with communicating aperturesformed through a predetermined portion thereof in positions lying adjacent saidentrained llexible track, and an air supply-means connected with said carrier chamber to introduce air under pressure into said chamber for dispersion through said chamber apertures into an area between said track and carrierto establish a given pressurized cushion` of air in said area to urge said track and carrier out of physical contact relation with respect to each other under operative conditions.-

v2. A 4liuid lubricated traction assembly comprising la flexible track, a carrier located within said liexible track,

' a drive unit also-located within said flexible track and connected to actuate said track, said carrier and drivel unit providing separated coacting complementary shapes having track guiding surfacesthcreon delining a given external contour, said liexible track encircling said `carrier and drive unit to provide a mobile supporting section to uphold both said carrier and the separate drive unit, said carrier comprising a hollow chamber having openings directed toward the supporting section of said 'ilexible track, and a fluid supply means having communication chamber to introduce fluid' under pressure said chamber openings into the vspace lying between said supporting section of said flexible track and the adjacent portion of the carrier to normally urge said carrier out of physical contact with respect to said track.

3. In the ii'uid lubricated track assembly inA claim 2, with the addition of auxiliary vents in an upper portion of the carrier chamber to direct uid into the space between the tractive inactive portion of the li-exible track and the next adjacent portion of the carrier to urge said inactive track 'out of physical Contact with respect to the upper portion of the carrier.

4. In the fluid lubricated track assembly in claim 2, with the addition of coacting elements on said track to engage non-apertured portions of said carrier to provide a limited seal therewith to aid in the retention of the liuid in the physical separation space between said track and carrier, saidcoacting elements also providing orientation means to hold the track upon said carrier and on saiddrive unit.l v

5. An air track assembly comprising a continuous liexible traction means delining apredetermined shape of openloop encircled by saidmeans, a hollow drive wheel filling a part of said openiloop and having contact with a portion of said traction means, a hollow carrier coacting with said drive wheel and supported upon said traction means to oecupythebalance of the available space in Y said open loop traction means, and air compression means connected with said hollow carrier to deliver air undery pressure into the hollow carrier, said carrier having air discharge apertures therein arranged to delivcr'air under pressureinto the space between said supported. carrier :and the supporting portion of said traction means to estab- -1ish an air cushion between Saidtraction means and the adjacent supported carrier.

'6. An'air track assembly as in claim 5 wherein said hollow drive wheell is provided with peripherally located openings disposed in the path` of said encircling traction .-means, and air inlet means are provided for communicadrive wheel and said air compresmeans including regulatory valves to selctivelycause tlow i of intake air from said hollow wheeland from said conduit means respectively.

'8. In an 'air track assembly as in claim 5 with the addi tion of coacting positive drive elements on said drive wheel and said traction means respectively to positively' convey the traction means about said carrier.

9. Power mechanism to propel a mobile vehicle comprising a carrier including a plenumv section, a flexible track entrained about said carrier and the plenum section thereof, drive means connected with s aid flexible track to move said track around said carrierand the plenum section,` and conduit means connected with4 said plenumf section to supply air under pressure to said section,

said plenum section being constructed of llexi'ble inliataf ble material and occupying a position over the ground engaging portion of-the llexible track whereby said plenum section and track are both adapted to liex and deform in passing over ground obstructions and irregular'i-l I ties, said plenum section being provided with air vent openings communicating with space between' the iiexible track andthe portion of the plenum section lying adjacent said track to establish a pressurized cushion of air in theaforesaid spaceto urge saidplenum section out of physical contact with said track.

l0. Power mechanism vtopropel a mobile vehicle comprising a load vsupporting carrier, a flexible track encircling said carrier exterior and providing propulsion'means to' convey said carrier over the ground, and drive-means to actuate said track about said carrier, vsaid track and carrier having coacting guide means thereon to maintain said respective units in operative relation with respect to each other, and said flexible track being constructed withy a hollow inliatableiinterior fot-"operative disposition between the carrierand the ground to provide a flexing and deformablel ground engaging track portion to absorb road shock transfer to said carrier and to negotiate road irregularities without carrier-interference, said carrier comprising a plenum, and conduit means connected with said plenum to supply air under -pressure to the plenum, said plenum 'being provided with vent openings communicating with a selected portion of the space between said plenum and track to establish a cushion ofypressurized air in said space to urge physical separation between said plenum and track.

1l. Ari a-ir track assembly comprising an air plenum section forming a box, a drive wheel, and a liexible track encircling said air box in and air conduit shoe means entrained over the wheel and spaced relation about said box, being connected with said box and disposed in'contactf,

with said track, said shoe means having air vents iunctioning to direct pressurized air against internal peripheral portions of said llexible track to establish an air cushion' between said track and 4said `shoe means to support the box 'within said encircling e'xible track.

l2. An air track assembly comprising an air plenum section forming a box, a drive wheel, and a exible track vpressurized air against internal peripheral portions of said flexible track to establish an air cushionbetween said track and said shoe means to supportthe box within said encircling ilexible track, said air conduit shoe means comprising a plurality of articulate air shoes carried by said box for operative disposition adjacent to the radially i11- ner surface portion of said flexible track.

13. An air track assembly comprising an air plenum section forming a box, a drive wheel, and a flexible track entrained over the wheel and encircling said air box, and air conduit shoe means connected with said box and=dis posed in contact with said track and functioning to direct pressurized air against internal peripheral portions of said exible track to establish an air cushion between said track and said shoe meansl tosupport the box within said encircling flexible track, said air conduit shoe means comprising a plurality of individually mounted sho'e's mov'ably connected with said box and presenting guide surfaces for riding within said flexible track, said shoes having air exhaust apertures in their respective guide'surfaces to 'discharge pressurized air between the shoes and the ad! jacent areas of the track at the shoe locations, and flexible air transfer means connected betweensaid box and each of said shoes to supply air to said shoes for discharge out? of the exhaust apertures of the shoes.

14. Power mechanism to propel a m'obile vehicle cornprising a vehicle carrier having a pressurized air plenum section, a looped flexible track, a drive wheel to move said At-rack,and a plurality of shoesdi'sposed in operative positions within and against said looped track, said plenum section being spaced from the track in a location 'remote from said shoes, and link means connected with said plenum section and with said shoes to allow relative mo- -tionrbetween said shoes and plenum section, said shoes being hollow and having openings located on the track contactingfaces thereof, and air conducting means connectedA with said plenum section and with said shoes to permit air transfer into said shoes for discharge against the vadjacent track to establish an air cushion between said shoes and-track.

15. In a power mechanism as in claim 14, wherein said link means are each pivotally connected with said plenum section and with saidshoes, said link means each including a lost motion connection at one of the pivotal locations l to accommodate shoe retraction. v v

16. In the combination in claim 15 including coacting stop means on the-link means and connected shoes to limitv the amount of relative motion between said connected members. v

17. In a power mechanism as in claim 14, wherein spring means are interposed between said plenum section and the shoes to normally maintain said shoes in their extended load carrying positions and to permit shoe retraction under track deformation when passing over ground obstructions,

2,987,347 Cook et al.` June 6, 1961 

1. AN AIR TRACK ASSEMBLY COMPRISING A CARRIER, A DRIVE WHEEL DISPOSED BEYOND ONE END OF THE CARRIER, AND A FLEXIBLE TRACK ENTRAINED OVER BOTH SAID CARRIER AND DRIVE WHEEL, SAID CARRIER AND DRIVE WHEEL TOGETHER PROVIDING COMPLEMENTARY HOUSING MEANS THAT FILL THE INTERIOR OF SAID FLEXIBLE TRACK, SAID CARRIER HAVING A HOLLOW CHAMBER WITH COMMUNICATING APERTURES FORMED THROUGH A PREDETERMINED PORTION THEREOF IN POSITIONS LYING ADJACENT SAID ENTRAINED FLEXIBLE TRACK, AND AN AIR SUPPLY MEANS CONNECTED WITH SAID CARRIER CHAMBER TO INTRODUCE AIR UNDER PRESSURE INTO SAID CHAMBER FOR DISPERSION THROUGH SAID CHAMBER APERTURES INTO AN AREA BETWEEN SAID TRACK AND CARRIER TO ESTABLISH A GIVEN PRESSURIZED CUSHION OF AIR IN SAID AREA TO URGE SAID TRACK AND CARRIER OUT OF PHYSICAL CONTACT RELATION WITH RESPECT TO EACH OTHER UNDER OPERATIVE CONDITIONS. 